How to Replace a Damaged Expansion Joint with Belzona 4521

In this video, we demonstrate an #expansionjoint replacement with Belzona 4521. #Belzona4521 is an elastomeric fluid designed for the repairs and replacement of building and expansion joints.

How-to step-by-step guidelines: 

1. Remove any existing joint sealants and a backer rod. The saturated joint filler should also be removed. 

2. Using a concrete edge grinder, scarify the sides and edges of the joint to remove the remaining sealant and to provide a firm substrate to which to bond. 

3. Vacuum or blow out all the debris, dirt and loose parts.

4. Insert a backer rod. Make sure that the backer rod is compressed and fits tightly into the joint. The size of the backer rod should be approximately 20% greater than the width of the joint. 

5. The depth of the backer rod should be one-half of the width of the joint.

6. Place the masking tape onto the edges of the joint before proceeding to conditioning. 

7. For the accuracy of each application, always follow the Manufacturer’s Instructions for Use. 

8. Mix Base and Solidifier of Belzona 4911 Conditioner. 

9. Using a short-bristled brush, apply the mixed conditioner to the walls of the joint. 

10. Then, proceed to the mixing of Base and Solidifier of Belzona 4521. 

11. Pour the mixed product into the joint. Once the material has been poured, tool the joint to the sides leaving the surface slightly concave. 

12. The masking tape should be removed before the product cures.